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EFFECTIVE USE OF SOLID HOUSEHOLD WASTE
Q.N.Khoshimov
J.F.Ungarov
A.A.Ataxojayev
E.A.Egamberdiev
L.M.Xabibullayeva
Tashkent State Technical University named after Islam Karimov
https://doi.org/10.5281/zenodo.15110989
Household waste is generated in places where people live, including workplaces. The
generated solid household waste is transported to specially designated areas by special
transport. As a result of a long stay of solid household waste in a stationary state in permanent
storage areas, the process of decomposition of the organic part of solid household waste occurs
as a result of biological changes under external influence. In the process of chemical and
biochemical changes in the decomposition reaction, a number of products are released, which
are dispersed into the air by the blowing wind and distributed among residential areas. At the
same time, soil, water and atmosphere are infected.
It is known that the disposal of solid household waste is a big problem in the world, and
its solution is approached differently everywhere. In Japan, after organized collection and
placement in garbage containers at the places where they are generated, solid waste is sent to
waste incineration plants. The energy generated by the incineration of waste is used to heat
water until it turns into steam. The energy of the steam is directed to special units, where the
mechanical energy of the steam is converted into electrical energy. The whole process occurs
without any negative impact on the environment. In addition, currently in industrially
developing countries, research is being conducted on obtaining composite materials using such
waste effectively. As a continuation of our research, we conducted research on obtaining wood-
polymer composites using local wood species.
The use of plastic waste and wood waste for the production of composites is a promising
solution to reduce the amount of waste in landfills. It is worth noting that wood waste in
landfills contains many types of wood, such as branches, leaves, and twigs, which significantly
affect the properties of wood polymer composites (WPCs) due to their chemical composition
and surface morphology. Therefore, in this research work, the effect of the types and
composition of wood waste on the mechanical and physical properties of WPCs processed
under natural weathering conditions was investigated. The ultimate goal of this work was to
produce environmentally friendly PBMCs from a composite of plastic waste and wood waste
generated in landfills by studying the effects of the types and composition of wood waste under
natural weathering conditions. The new information is useful for the construction and
infrastructure sectors, such as for flooring, fences, cladding, roofing, walls and wood products
installed on the exterior of buildings that are resistant to natural weathering. In addition, the
results of the study are expected to increase interest in developing PBMC products from waste
materials to reduce the amount of waste in landfills.
The waste materials selected for the study were plastic bags, wooden branches, twigs, and
leaves collected at a landfill in the Tashkent region. Before recycling the plastic bags, they were
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washed with a liquid detergent solution and rinsed three times in water. Then they were cut
into 0.5-1.5 cm pieces using a cutting mill and granulated using an extruder at temperatures
from 200 to 225. Then the material was processed by placing it in a hot press.
Figure 1. a) plastic waste, b) wood branches, c) leaves and d) other tree leaf waste
In the initial stage of the study, we began by studying the chemical composition of wood
waste. According to this, the amount of cellulose, hemicellulose, lignin, and ash in the study
object was determined, and this information is presented in the table below (Table 1).
Table 1 Chemical composition of wood waste types
Types of wood used for research
Chemical composition in percentage (%)
Cellulose
Hemicellulose
Lignin
Ash
content
walnut tree branches
47.5
22.6
27.5
2.4
walnut tree leaves
40.7
35.7
20.5
3.1
thick branches of a walnut tree
52.8
22.3
22.2
2.7
paulownia tree branches
46.8
24.4
26.5
2.3
paulownia tree leaves
42.5
35.4
18.9
3.2
thick branches of the paulownia tree
50.5
25.5
21.5
2.5
poplar tree branches
46.5
25.1
25.8
2.6
poplar tree leaves
39.5
37.6
19.8
3.1
thick branches of a poplar tree
48.5
27.8
20.9
2.8
Processes for obtaining wood polymer composites.
The raw materials prepared for
the experiment were mixed with wood waste flour and pigment in a co-rotating twin-screw
extruder. The screw rotation speed was adjusted to 60 rpm until the extrusion temperature
was fully mixed in the range of 165-185°C. Then the extruded mass was prepared for the press
before the extruder. For this, it was preheated in a hydraulic compression machine at a
temperature of 300°C-350°C under a pressure of 3.55 MPa for 5-7 minutes and molded under
a pressure of 6.90 MPa for 15 minutes; the WPC samples were then cooled under a pressure of
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6.90 MPa for 15 minutes. Finally, the WPC panels were prepared as samples for testing
mechanical and physical properties.
Table 2 Composition of wood-polymer composites in the experiment
Natural weathering test
The experiments were conducted on samples installed around a pond in a summer cottage
near the Chirchik River in Ghazalkent district. The climatic conditions near the river were
directly exposed to natural weathering. The samples were exposed to natural weathering for 6
months during the rainy season from July 2024 to December 2024. The average relative
humidity during the experimental period was 82.03% RH, the total precipitation was 2366.8
mm over 117 days, and the temperature ranged from 22.8 to 34.8°C. The samples were
characterized after exposure for 2, 4, and 6 months.
Physical and mechanical properties of wood-polymer composites
Research samples
Tensile strength in
composites, MPa
Elasticity, MPa
Deformation
WPC 1
39.85
1850.30
1.28
WPC 2
38.92
1793.65
1.29
WPC 3
37.08
1692.96
1.73
WPC 4
36.96
1583.10
1.78
WPC 5
36.92
1548.14
1.82
The results of the tensile strength, elastic model and deformation properties tests of all
the composites can be seen in Table 3. From the results, it can be seen that the above physical
and mechanical properties of the composites are higher in samples with a higher content of
walnut tree waste flour. The maximum tensile strength was observed in sample-1. The addition
of 6% MAPPS improved the interfacial adhesion. In addition, when the amount of MAPPS
increased, the hardness of the material increased. Accordingly, the deformation values
decreased due to the weak boundary between the matrix and the additives. Taking into account
the above, it can be seen from the table that the tensile strength increased in samples with a
lower content of MAPPS in the composition, but the elastic model decreased. On the other hand,
the elastic modulus increased with an increase in the amount of walnut tree waste flour. As a
result, when the amount of MAPPS increased from 2% to 6%, the elastic modulus and tensile
Samples
are
marked
Composition composition
Amount
of
crushed
leaves
(%)
Amount of
wood flour
produced
from twigs
(%)
Amount of
wood flour
produced from
thick branches
(%)
Amount (%) of
Molein Angridir
Polypropylene
Copolymer
(MAPPS)
Amount of
plastic
waste (%)
WPC1
4
14
20
2
60
WPC 2
5
12
30
3
50
WPC 3
6
10
40
4
40
WPC 4
7
8
50
5
30
WPC 5
8
6
60
6
20
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strength of the 4 types of wood composites also increased. MAPPS provided a stronger
boundary between the polymer matrix and the additives.
Conclusion.
This study showed that the exposure time, as well as the types and
composition of different wood wastes, had a significant effect on the physical and mechanical
properties of WPC materials. Although all properties of WPC s deteriorated with increasing
natural weathering, the amount of wood waste in all wood types increased, and WPC s became
stiffer. Increasing the amount of wood waste from 30% to 60% in wood polymer composites
increased the percentage loss of MOR, MOE, SWS and hardness properties, which is related to
microcracks on the surface of WPC. Based on the results of this work, wood polymer composites
based on branches are proposed for the production of WPC materials for construction and
building products. In addition, it was concluded that solid household waste can be used as a
raw material in the production of WPC s. Waste recycling is a promising solution to reduce the
amount of various waste in landfills.
Foydalanilgan adabiyotlar/Используемая литература/References:
1.
Klason, C. The efficiency of cellulosic fillers in common termoplastics / C. Klason, Kubat
and H.E.Stromvall // Filling without processing aids or coupling agents. International J. of
Polymeric materials. – Part I. 10: – 1994. – P. 159-187.
2.
Бикбау, М.Я. Производство супернаполненных пластмасс - искусственного дерева,
композиционных материалов и изделий. Технологическая и технико- экономическая
оценка [Электронный ресурс] – Электрон. текст. дан. – Режим доступа:
http://bikbau-
marsel.narod.ru /olderfiles/1/kompozit.pdf
(Дата обращения: 24.08.2015)
3.
Термопластичные древесно-полимерные композиты в интерьере [Электронный
ресурс] – Электрон. текст. дан. – 12.10. 2006. – Режим доступа
обращения: 28.03.2015).
4.
Будников, И.В. Экологически чистые древесно-полимерные композиты / И.В.
Будников, O.A. Парамонова // [Электронный ресурс]. – Электрон. текст. дан. – 17.05.2012.
– Режим доступа:
http://conf.bstu.ru/conf/docs/OQ11/0172.doc,
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